I mentioned it in a side note that I trimmed because there were so many that it spilled into the footer (faster to trim the article than to fix the CSS,) but Microsoft is the only implementation of the big three that doesn't mark the move constructor here as nothrow. The standard doesn't require it so it's valid for MSVC to do things the way they do, it just creates problems like this that would arguably be harder to find the cause of if one had to build code for multiple platforms.